Boiler control system



Sept. 8, 1931. 1,822,133

J. W. DOBLE, NOW BY JUDICIAL CHANGE OF NAME W. DOBLE BOILER CONTROL SYSTEM Original Filed Dec. 13, 1919 III/Ali"? IV 0051.: BY

A rrauns Patented Sept. 8, 1 931 "jimirso .srA'ras PATENT. OFFICE] JESSE w. noBLE, now By .mmcrn. CHANGE or NAME WARREN DoBLE, or BERKELEY,

FIIALIIORNIA, ASSIGNOR '10 DOBLE LABOBATORIM -OF SAN FRANCISCO, CALIFOR- NIA, A CORPORATION OF CIIIFOBNIA Original application filed December 18, 1919, Serial No. $344,741.

BOILER common SYSTEM 1928. Serial No. 675,850. Divided and this application filed August 3, 1925. Serial No. 48,012.

This inventionrelates to a system for controlling the temperature and pressure conditions in a'steam boiler, and more particularly to such a system in which the water or other heat absorbing medium is supplied to the boiler automatically in accordance with prescribed conditions of temperature and pressure. 1

This application is a division of my application Serial No. 675,850 filed November 20, 1923, for boiler control system, which application is a division of my application Serial No. 344,741 filed December 13, 1919, which has matured into U. S. Letters Patent No. 1,481,460 dated January 22, 1924.

An object of my invention is to provide a boiler control system in which the boiler feed Water supply and the fuel supplied to the boiler furnace is controlled by conditions obtaining in the boiler.

Another object of the invention is to provide a boiler control system in which the boiler feed water supply and the air for the combustion of the fuel is controlled by con- 4 ditions obtaining in the boiler.

My invention possesses other advantageous features,some of which with the foregoing, will be set forth at length in the following description, where I shall outline in full that form of the invention which I have selected for illustration in the drawing accompanying and forming part of the pres ent specification. Although I have shown in the drawing but one embodiment of my invention, I do not desire to be limited thereto, since the invention as expressed in the claims may be embodied in other forms also.

Referring to the drawing:

The single figure is a diagrammatic representation of an installation embodying my' invention.

In the present instance the boiler 1 is heated by the combustion of liquid fuel, such as kerosene, distillate, or oil. In order to vaporize the fuel so that it may serve most efficiently as a heat producing medium, it is conducted to a rotating cup 2 through a pipe or conduit 3,'leading from a small tank 4 n which in turn connects to a source of supply by the aid of a pipe 5. The cup 2 is encased in a housing 6 which is in communication with the. combustion chamber of boiler 1 through a passageway 22. The cup 2 may be rotated in any appropriate manner, as by the aid of a small electric motor 8, which may also serve to rotate a fan 9 for project ing the sprayed fuel into the combustion chamber. Appropriate provision may be made in the combustion chamber to ignite Divided and application filed November 20,-

and comprises a reciprocating pump 10, its

discharge being connected as by pipe 11 to the boiler, and arranged to be driven by the crank and rod device 12. This device is coupled to the engine operated from the boiler, so that the operative parts of pump 10 are continuously in motion during the operation of the engine. The intake to the pump is controlled by a valve 13 in a chamber 1 1' connected as by pipe 15 to a source of liquid. The valve is so arranged that it seats whenever the pump 10 is on its discharge stroke, but unseats in response to the reduction in pressure above it, when the pump is on its suction stroke. This type of pump as thus described, may readily be rendered inactive irrespective of the movement of the parts 12, by'moving and retaining the valve 13 in its unseated position. By holding the inlet valve unsea'ted, the pump is rendered inoperative to introduce water into the boiler. A check valve 60 in the pipe 11, be-, tween the boiler and the pump prevents dis-- matically illustrated, includes a mechanically movable lever 16, the position of which is dependent upon the pressure existing in the.

boiler 1. This may be accomplished for example by the aid of a cylinder 17 which is connected to the boiler 1, and which has a piston 18 mechanically attached to the lever 16. An increase in pressure causes lever 16 to rock in a clockwise direction against gravity or a spring 16 The lever is so arranged that its movement regulates the flow of fuel to the cup 2, as by aid of a valve 19'and a connection 20. In order to ensure complete oombustion at all times, and that no excess air is supplied to absorb heat wastefully, another mechanical connection 21 may be provided. to a butterfly valve 53 which controls the" amount of air that can be supplied to the combustion chamber through passageway 7.

Air is discharged by the blower 9 through as to maintain thispressure substantially uniform. I,

The temperature control device includes a rod'23 extending into a tubular dead ended opening 24 in the boiler, so as to be subjected to the boiler temperature. Therod' and the tube have different coeflicients of expansion,

. so that the outer end of the rod is moved due to variations in temperature. The movement of the outer end of the rod is caused to operate electrical contacts, such as 25 and 26, which cooperate with stationary, spring pressed contacts 27 and 28. The contacts 25 and 26 are arranged on a disk 29 carried by the end of the rod. The temperature control is such that an excessive or dangerous rise in temperature is prevented. The contacts 26 and 28 serve to control the fuel feed, the supply of air and the circuit of the blower motor, and are so adjusted that they efi'ect this controlling only upon the existence of undesirable high temperatures.

The arrangement by which this result is accomplished may take the form of an electromagnetically operated valve 30 in the fuel tank 4. lhis valve is arranged to be urged,

as by gravity, to its seated position, whereby 5 it closes the fuel supply pipe 3, but'it is held,

' during normal operation, away from its seat by the aid of a solenoid 31. The energizing circuit for this. solenoid may be traced as follows: from a common ground return 32, to a source of electrical energy 33, a manually operable switch 34, connection 35, a pair of normally closed contacts 36 (which open only in response to excessive pressure conditions, operating on arm 16 mechanically controlling these contacts), connection 37, contacts 26 and 28, connection 38, solenoid 31, and

ground 39. By this arrangement the flow of. fuel will be interrupted by valve 30 whenever either excessive temperature or pressure conditions, or both, exist. For normal temperatures and pressures, contacts 36, and.

feed of fuel is interrupted in the manner just described, the dropping of valve 30 is caused to operate a pair of contacts 40 and 41 which control .the motor 8. Thus when the fuel feed is stopped, the motor circuit is opened at these contacts. The energizing circuit for motor 8 may be traced as follows from ground 32 to source otelectricity 33, switch 34, connection 42, contacts 41 and 40, motor 8, back to ground at 43.

The control of the feed water pum 10 will now be described. Normally the va ve 13 is permitted to follow the reciprocations of this pump, to seat and unseat on the discharge and such stroke respectively. A solenoid 44 is arranged to be energized to hold the valve unseated and thus render the pump 10 inactive. This occurs whenever the pressure in the boiler rises to an objectionably' high value, and is accomplished by the aid of a stati onarycontact 45 and a contact 46 movable in accordance with the movement of lever "arm 16. When this arm moves a substantial distance in response to a.predetermine d increase in pressure in boiler 1, the contacts 45, 46 close, and the solenoid 44 is energized, unseating the valve 13' and disabling the pump until the pressure is reduced to a normal value. The energizing circuit for the solenoid 44 may be traced as follows: from ground32, to source of electricity 33, switch 34, connection 47, contacts 46 and 45, connection 48, connection 49, solenoid 44, and

ground 50. It is to be noted at this point that the contacts 45 and 46 are operated when the excessive pressure in the boiler is caused for example by the introduction of water by the feed pump, as when the automobile upon which the boiler is installed is traveling down a long grade, and the engine is turning over, operating the pump 10.

Means are also provided for controlling the introduction of feed water intothe boiler by temperature conditions withinthe boiler, to prevent flooding of the boiler when the tem erature therein is low. This is accomplis ed by rendering the pump 10 inoperative to punfp water when the boiler temperature is below the predetermined minimum. Connected to the solenoid 44', which controls the.

valve 13' of the pump, is a temperature controlled circuit 51-'5249 which is connected in parallel with the pressure control circuit. The contacts 25 and 27 the relative positions of which are controlled by boiler temperature conditions, are arranged in the circuit 515249. VV-hen the temperature of the boiler falls below the predetermined minimum, the contacts and 27 are brought into engagement, closing the circuit through the solenoid 44, raising the valve 13 from its seat and rendering the pump inactive. When the temperaturesubsequently rises above the predetermined minimum, the contacts 25 and 27 are separated, the solenoid 44 is de-energized and the pump functions to-introduce water into the boiler.

The operation of the system is as follows: to set the boiler into operation, it is necessary to close the switch 34, either manually or in any other way. The valve 30 will then be opened, to permit fuel to feed to the cup 2, the control circuit for this valve being closed at contacts 36, and 26-2 8. The opening of valve 30 causes contacts and 41 to close, and the motor 8 is energized thereby. Fuel is then vaporized by cup 2 and is projected into the combustion chamber by the fan 9 where it is ignited by any suitable device.-

The boiler 1 is now in full operation. By aid of valve 19, the pressure is maintained within the desirable predetermined limits. However, in case this pressure for any reason becomes too high, the circuit for electromagnet 31 is abruptly interrupted at contacts 36 and the burner becomes inoperative.

At the same time pump 10 is inactive due to engagement of contacts 45 and 46. Upon a return to normal pressure, the flow of fuel and operation of motor 8'is automatically resumed. Excessive temperatures will also disable the burner apparatus, by aid of rod 23' and contacts 2628. Regulation of boiler temperature is also effected by the aid of contacts 2527, and solenoid 44, as has been already described. The pump 10 cannot function unless the temperature is above a definite lower limit imposed by these contacts, and unless the pressure is below a definite higher limit imposed by contacts 45 and, 46. It is thus seen that the functioning of pump 10 is accomplished only when the system demands it. I claim; 7 1. In combination, a liquid heater, a pump for supplying liquid to said heater, anelectrie circuit for disabling said pump, a thermostat responsive to temperatures in said heater below a predetermined minimum for completing said circuit to disable said pump, means for supplying fuel to said heater, a

pressure responslve device actuated by pressures in said heater above a predetermined maximumfor completing said circuit to disable said pump and for disabling said fuel supplying means, and means responsive to said pressure responsive device and to said thermostat in series for abruptly disabling said fuel supplying means. 2. Incombination, a liquid heater, means for supplying liquid to said heater, means for disabling said supplying means, a thermostat responsive to temperatures in said heater below a predetermined value for activating said disabling means, means for supplying fuel to said heater, means actuated by pressures in said heater above a predetermined value for activating said disabling means and for disabling said fuelsupplying means, and means responsive to said pressure actuated means and to said thermostat in series for disabling said fuel supplying means.

3. In combination, a liquid heater, means for supplying liquid to said heater, a thermostat responsive to temperatures in said heater below a predetermined value for disabling said liquid supplying means, means for supplying fuel to saidheater, means actuated by pressures in said heater above a predetermined value for disabling said liquid supplying means and for disabling said fuel supplying means, and means responsive to said pressure actuated means and to said thermostat in series for disabling said fuel supplying means.

4. In combination, a liquid heater, means for supplying liquid to said heater, temperature responsive means for disabling said liquid supplying means, means for supplying fuel to said heater, pressure responsive means for disabling said liquid supplying means and said fuel supplying means, and

means responsive to said pressure responsive means and said temperature responsive means in series for disabling said fuel supplying means.

In testimony whereof, I have hereunto set my hand.

JESSE DOBLE. 

